Step 11: Jam It All In

Step 12: Rejoice

Well thats about it actually. You can now either charge up the battery via the mini USB port on the Charging Circuit or via Solar power. The red sta...

One of the most fun and useful projects on instructables is to create your very own solar USB/ iPhone charger. They're not overly difficult to make, nor are the parts overly expensive or hard to find. For the most part they do a rather good job of charging up small gadgets. Mostly.

The big flaw in the DIY solar charger world are the batteries. Nearly all the designs on instructables (including all of my designs) use standard NiMh rechargeable batteries. They're cheap, easy to find, and very safe to use. The problem is that their capacity and voltage are both low, and the gadgets we keep wanting to charge are getting bigger and better batteries.

For instance an iPhone 4 has a 2,000mAh battery inside of it. Now that isn't too tough to charge up decently with a well made solar charger using 2 or 4 AA batteries. On the other hand an iPad 2 has a 6,000mAh battery pack on it. Not so easy to charge up.

The solution for these problems is to ditch NiMh batteries and turn to Lithium batteries.

In this guide I will show you how to make your very own Lithium battery charger. One that is cheap to make, easy to build, and most importantly safe to use.

(Oh and help me win the Instructables Green Tech Contest by voting for this project! An iPad would be great for my classroom! Even better, I'll build a massive Lithium powered charger to run the iPad. It'll be 100% green in my classroom.)

I was wanting to ask about the blocking diode no-one really explains why you pick that diode say over zener diode 1n437 5.6v. The reason i ask is iam attempting to build my own solar charger still waiting on alot of the parts to arrive. the solar cell will be 5.5v 266ma going to 4x 18650 cells in parallel setup. Will the zener diode that i have choosen work for the solar cell that i have.

Unfortunately, you can't just add LEDs in and expect it to show a charge. You'd need the right kind of voltage meter or monitoring chip. You could easily wire in a small LED voltmeter (they're all of $4 on eBay) and that would give you a general idea of how charged it is. Otherwise the charge controller board shows when it's full.

sssoooo.... wheres the lithium kit from the video on the website? all i see is this massive and expensive unit that has dual charging ports. where can i buy a kit that uses a simple Li-ion battery, and one usb connection fairly cheaply?

The parts are all still on the website. The new version addresses several issues that customers had, and gives a higher output and better charging. (The old version couldn't charge a tablet due to low amperage output. The new version can.) The prices are about the same as well between the old and new version.

how can i charge & use the lipo to charge my phone at same time? (solar charging Lipo -> lipo charging phone -> )? at same time while walking :) (panel installed on my bag or something, or cars front window)

hi plz answer me plz can I connect 3 or 4 AA batteries directly to the usb if not!can u please tell me what else can I use!I can't find charging controlers I cant access these things I m living in Afghanistan! can u plz plz help me make this stuff with easiest things!do you know I m talking resistors and other things from recycle electronics plz help me if one of u guys know! my email idris.amiry@hotmail.com BEST REGARDS: Edris

how can i charge & use the lipo to charge my phone at same time? (solar charging Lipo -> lipo charging phone -> )? at same time while walking :) (panel installed on my bag or something, or cars front window)

I made this neat little charger but I need a little help. It works fine with my old Ipod but it won't charge my Iphone 5. I bought the booster from BrownDogGadgets and modified it by taking out the battery contacts. ( I may have bought the wrong booster) I am working on making another one. But anyhow I found that this circuit would charge my Iphone 5 as long as I had the circuit in line with my car battery as it charged the Lithium Battery and my phone. That tells me that everything is all right. I just need more power or current flowing. I am considering adding another battery to the circuit. Any advise is greatly appreciated.

1. I believe it is no problem as long as you protect your solar panel with a diode. However, the solar panel would only be able to contribute any power if the voltage is higher than the input USB power of 5V. Onto this the threshold voltage of the diode needs to be added too.

I found a cheaper way to get the items needed. I got a 12,000mAH battery and a lithium charge controller/3 to 5 volt Booster circuit and a case for $18 on Rakuten and I also got a 6 volt 320mA Solar panel on Ebay for $8.

Hi there, not sure if you're responding to comments, but I am trying to reuse an old iphone 4 battery for this project, and the contacts are very confusing! I was wondering if you had any experience with this? Mr Google couldn't help me out this time...

Thanks for noticing the slight change! We have the positive from the lithium charge controller going to the switch and then to the positive on the usb port. In our picture the usb is covered with hot glue. We added the switch because the small red usb light being on all the time was draining the battery slowly. I believe Josh Zimmerman sells one with out a light or shows how to take it off the one he sells. Let us know if that helped and check out our site at catsscience.com!

Thank you for the detailed project. I've zero interest or knowledge of electronics prior to finding this site, now i'm stoked about building this and I have all the pieces to make my first project...at least I think so, we'll see. Thanks again for peaking my interest in something I think I can really use and will benefit me to have.

But please help, Can I use double AA batteries with the lithium charging board, if I use 3 aa batteries i'll be at 4.5V, shouldn't that work? I already own many rechargeable AA's and zero lithium batteries.

My reason in wanting to try this is for the lighting indications. I'll know when fully charged and they wont be over charged, etc.

I followed your project but I am having a problem with the phone battery not charging even with phone off. I wired this as to the specs and double checked....Do I need to put another blocking diode to the USB controller?